There is a Legacy version
here.
Lethal Finisher [one-action] Feat 18Death Finisher Swashbuckler Source Player Core 2 pg. 169Prerequisites precise strike 6d6
You stab your foe in a vital organ, possibly killing them outright. Make a Strike. On a success, you forego your precise strike damage from the finisher. Instead, your target takes additional precision damage based on a Fortitude save against your class DC. If your Strike was a critical hit, the target's saving throw outcome is one degree worse.
Critical Success You deal 6 precision damage.
Success You deal 6d6 precision damage.
Failure You deal 12d6 precision damage.
Critical Failure You deal 18d6 precision damage.
Traits
Death: An effect with the death trait kills you immediately if it reduces you to 0 HP. Some death effects can bring you closer to death or slay you outright without reducing you to 0 HP.
Finisher: Finishers are spectacular finishing moves that use your panache. Finishers can be used only with weapons that deal additional damage with precise strike (agile or finesse melee weapons or unarmed attacks, for most swashbucklers). You can use a finisher only if you have panache, and you lose your panache immediately after performing a finisher. Once you use a finisher, you can't use actions that have the attack trait for the rest of your turn.
Some finisher actions also grant an effect on a failure. Effects added on a failure don't apply on a critical failure. If your finisher action succeeds, you can still choose to apply the failure effect instead. For example, you might do this when an attack deals no damage due to resistance.